This invention is directed to a clean air facility and more particularly to a clean air facility which is of a class 10 type or better, that is, one which produces a clean air throughput having less than 10 particles of a size 0.5 micron or greater per cubic foot of air.
Heretofore, clean air rooms have been of two main types: those which are fixed in place as well as those that are portable. Applicant has the following patents which are related to the present invention: U.S. Pat. Nos. 4,732,592; 4,804,392 and 4,900,342. Another prior art patent known to applicant is U.S. Pat. No. 4,304,224, which is also related to clean air facilities.
It has been determined that in order to provide a class 10 clean air facility friction of internal components used in construction must be held to a minimum; the air must be uniformly distributed. In most clean rooms air changes per hour are 100-200 ACPH (air changes per hour). But, in some cases a minimum number of air changes per hour are desirable and air changes per hour must be held to a minimum. In addition, it is desirable that the facility be transportable.
This combination of desired features has not been provided by the known prior art. For instance, the facility of U.S. Pat. No. 4,304,224 has many sources of friction which generate airborne particles that contaminate the air flow. The air is not uniformly distributed and has a maximum of 20 air changes per hour. The facility is not transportable and is specifically designed as a sterile chamber rather than as a clean air facility.